Molecular Diagnostics for Fungicide Resistance in Plant Pathogens

A single point mutation in the novel PvCesA3 gene confers resistance to the carboxylic acid amide fungicide mandipropamid in Plasmopara viticola

“…Thus, it is not surprising, that resistance in P. viticola field populations evolved in France shortly after the introduction of dimethomorph, one of the first CAA fungicides introduced to the market. Generally, resistance to fungicides is based mainly on changes in the target enzyme (affecting affinity to the inhibitor), but also altered influx/efflux balances were reported (Sierotzki and Gisi, 2003). Although the mechanism of resistance is not necessarily associated with the primary site and biochemical mode of action of a compound, it can provide evidence to determine the site Table 4 Amino acid substitutions in CesA gene products of 41 P.viticola single-sporangiophore isolates and correlation to MPD sensitivity.…”

Characterization and selection ofBacillus sp. strains, effective biocontrol agents againstFusarium oxysporum f. sp.radicis-lycopersici, the causal agent of Fusarium crown and root rot in tomato

“…Yield losses were ranged from 20-60% (Jarvis et al, 1983). Chemical fungicides are typically used to manage the disease; however, repeated applications may be responsible for the appearance of fungicide-resistant strains of the bacteria (Benhamou and Belanger, 1998;Sierotzki and Ulrich, 2003).…”

Evolution of Qol resistance in Plasmopara viticola oospores

“…Since the discovery that QoI resistance in P. viticola correlates with a single nucleotide polymorphism in the cytochrome b gene leading to an amino acid change at position 143 (G143A) (Sierotzki et al 2005;Chen et al 2007), molecular methods allow a fast and accurate detection of QoI resistance by an allele-specific, real-time PCR assay (Sierotzki and Gisi 2003). The possibility of using this highly sensitive method improved the possibility of monitoring the spread of resistant strains and studying the evolution of fungicide resistance at the population level (Ma and Michailides 2005;Sierotzki et al 2005).…”

“…The possibility of using this highly sensitive method improved the possibility of monitoring the spread of resistant strains and studying the evolution of fungicide resistance at the population level (Ma and Michailides 2005;Sierotzki et al 2005). In general, QoI sensitivity can be monitored by collecting P. viticola strains in vineyards and evaluating their sporulation on leaf discs treated with different fungicide concentrations (www.frac.info) or by molecular methods (Sierotzki and Gisi 2003).…”